Parasitic light absorption, rate laws and heterojunctions in the photocatalytic oxidation of arsenic(III) using composite TiO2/Fe2O3

Composite photocatalyst-adsorbents such as TiO2/Fe2O3 are promising materials for the one-step treatment of arsenite contaminated water. However, no previous study has investigated how coupling TiO2 with Fe2O3 influences the photocatalytic oxidation of arsenic(III). Herein, we develop new hybrid experiment/modelling approaches to study light absorption, charge carrier behaviour and changes in the rate law of the TiO2/Fe2O3 system, using UV-Vis spectroscopy, transient absorption spectroscopy (TAS), and kinetic analysis. Whilst coupling TiO2 with Fe2O3 improves total arsenic removal by adsorption, oxidation rates significantly decrease (up to a factor of 60), primarily due to the parasitic absorption of light by Fe2O3 (88% of photons at 368 nm) and secondly due to changes in the rate law from disguised zero-order kinetics to first-order kinetics. Charge transfer across this TiO2-Fe2O3 heterojunction is not observed. Our study demonstrates the first application of a multi-adsorbate surface complexation model (SCM) towards describing As(III) oxidation kinetics which, unlike Langmuir-Hinshelwood kinetics, includes the competitive adsorption of As(V), and we further highlight the importance of parasitic light absorption and catalyst fouling when designing heterogeneous photocatalysts for As(III) remediation

Anisotropic generalization of Stinchcombe's solution for conductivity of random resistor network on a Bethe lattice

Our study is based on the work of Stinchcombe [1974 \emph{J. Phys. C} \textbf{7} 179] and is devoted to the calculations of average conductivity of random resistor networks placed on an anisotropic Bethe lattice. The structure of the Bethe lattice is assumed to represent the normal directions of the regular lattice. We calculate the anisotropic conductivity as an expansion in powers of inverse coordination number of the Bethe lattice. The expansion terms retained deliver an accurate approximation of the conductivity at resistor concentrations above the percolation threshold. We make a comparison of our analytical results with those of Bernasconi [1974 \emph{Phys. Rev. B} \textbf{9} 4575] for the regular lattice.Comment: 14 pages, 2 figure

Dizajniranje i sinteza novih derivata tiofenkarbohidrazida, tienopirazola i tienopirimidina s antioksidativnim i antitumorskim djelovanjem

2-Amino-5-acetyl-4-methyl-thiophene-3-carboxylic acid ethyl ester (1) and 5-acetyl-2-amino-4-methylthiophene-3-carbohydrazide (2) were synthesized and used as starting materials for the synthesis of new series of 1-(5-amino-4-(3,5-dimethyl-1H-pyrazole-1-carbonyl)-3-methylthiophen-2-yl) ethanone (3a), 1-(5-amino-4-(4-chloro-3,5-dimethyl-1H-pyrazole-1-carbonyl)-3-methylthiophen-2-yl) ethanone (3b), 1-(4-methyl-2-amino-5-acetylthiophene-3-carbonyl) pyrazolidine-3,5-dione (4), (Z)-N\u27-(4-methyl-2-amino-5-acetylthiophene-3-carbonyl) formohydrazonic acid (5a), (Z)-ethyl-N\u27-(4-methyl-2-amino-5-acetylthiophene-3-carbonylformo hydrazonate (5b), 6-acetyl-3-amino-2,5-dimethylthieno2,3-dpyrimidin-4(3H)-one (8), 5-methyl-3-amino-2-mercapto-6-acetylthieno2,3-dpyrimidin-4(3H)-one (10) and 5-methyl-6-acetyl-2-thioxo-2,3-dihydrothieno2,3-dpyrimidin-4(1H)-one (12) as potential antioxidant and antitumor agents. Pharmacological results showed that compounds 6a, 6b, 8, 10 and 12 exhibited promising antitumor and antioxidant activity.Etilni ester 2-amino-5-acetil-4-metil-tiofen-3-karboksilne kiseline (1) i 5-acetil-2-amino-4-metiltiofen-3-karbohidrazid (2) sintetizirani su i upotrebljeni kao reaktanti u sintezi novih spojeva 1-(5-amino-4-(3,5-dimetil-1H-pirazol-1-karbonil)-3-metiltiofen-2-il) etanona (3a), 1-(5-amino-4-(4-klor-3,5-dimetil-1H-pirazol-1-karbonil)-3-metiltiofen-2-il) etanona (3b), 1-(4-metil-2-amino-5-acetiltiofen-3-karbonil) pirazolidin-3,5-diona (4), (Z)-N\u27-(4-metil-2-amino-5-acetiltiofen-3-karbonil) formohidrazonske kiseline (5a), (Z)-etil-N\u27-(4-metil-2-amino-5-acetiltiofen-3-karbonilformo hidrazonata (5b), 6-acetil-3-amino-2,5-dimetiltieno2,3-dpirimidin-4(3H)-one (8), 5-metil-3-amino-2-merkapto-6-acetiltieno2,3-dpirimidin-4(3H)-ona (10) i 5-metil-6-acetil-2-tiokso-2,3-dihidrotieno2,3-dpirimidin-4(1H)-ona (12) kao potencijalnih antioksidansa i citostatika. Farmakološka ispitivanja ukazuju na to da spojevi 6a, 6b, 8, 10 i 12 imaju značajno antitumorsko i antioksidativno djelovanje

Extraperitoneal urine leak after renal transplantation: the role of radionuclide imaging and the value of accompanying SPECT/CT - a case report

<p>Abstract</p> <p>Background</p> <p>The differentiation of the nature of a fluid collection as a complication of kidney transplantation is important for management and treatment planning. Early and delayed radionuclide renography can play an important role in the evaluation of a urine leak. However, it is sometimes limited in the evaluation of the exact location and extent of a urine leak.</p> <p>Case Presentation</p> <p>A 71-year-old male who had sudden anuria, scrotal swelling and elevated creatinine level after cadaveric renal transplantation performed Tc-99 m MAG3 renography to evaluate the renal function, followed by an ultrasound which was unremarkable. An extensive urine leak was evident on the planar images. However, an exact location of the urine leak was unknown. Accompanying SPECT/CT images confirmed a urine leak extending from the lower aspect of the transplant kidney to the floor of the pelvic cavity, presacral region and the scrotum via right inguinal canal as well as to the right abdominal wall.</p> <p>Conclusions</p> <p>Renal scintigraphy is very useful to detect a urine leak after renal transplantation. However, planar imaging is sometimes limited in evaluating the anatomical location and extent of a urine leak accurately. In that case accompanying SPECT/CT images are very helpful and valuable to evaluate the anatomical relationships exactly.</p

Sinteza, in vitro antitumorsko ispitivanje i radiosenzitirajuće vrednovanje novih derivata 4-[3-(supstituiranih)tioureido]-N-(kinoksalin-2-il)benzensulfonamida

Sulfonamides and quinoxaline derivatives possess many types of biological activities and have been recently reported to show substantial antitumor activity. This paper reports the synthesis of novel thioureidosulfaquinoxaline derivatives. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against a human liver cell line (HEPG2) and showed higher activity than the reference drug doxorubicin. 4-(3-(4-Ethylbenzoate)thioureido)-N-(quinoxalin-2-yl)benzenesulfonamide (9) (IC50 = 15.6 µmol L1), N-(pyridin-2-yl)-4-(3-(4-(N-quinoxalin-2-yl-sulfamoyl)phenyl)thioureido)benzene-sulfonamide (10) (IC50 = 26.8 µmol L1) and N-(quinoxalin-2-yl)-4-(3-(4-(N-thiazol-2-ylsulfamoyl)phenyl)thioureido)benzenesulfonamide (11) (IC50 = 24.4 µmol L1) were the most potent compared to doxorubicin (IC50 = 71.8 µmol L1). The most potent compounds 9, 10 and 11 were evaluated as radiosensitizing agents by subjecting the compounds to γ-irradiation (8 kGy).Derivati sulfonamida i kinoksalina imaju raznoliko biološko djelovanje, između ostalog i antitumorsko djelovanje. U radu je opisana sinteza novih derivata tioureido sulfakinoksalina. Svim novim spojevima ispitano je antitumorsko djelovanje in vitro na humanoj staničnoj liniji jetre (HEPG 2). Svi ispitani spojevi pokazuju jači učinak nego referentni lijek doksorubicin. Najjači učinak imali su 4-(3-(4-etilbenzoat)tioureido)-N-(kinoksalin-2-il)benzen-sulfonamid (9) (IC50 = 15,6 µmol L1), N-(piridin-2-il)-4-(3-(4-(N-kinoksalin-2-il-sulfamoil)fenil)tioureido)-benzen-sulfonamid (10) (IC50 = 26,8 µmol L1) i N-(kinoksalin-2-il)-4-(3-(4-(N-tiazol-2-ilsulfamoil)fenil)tioureido)benzen-sulfonamid (11) (IC50 = 24,4 µmol L1), dok je IC50 vrijednost bila 71,8 µmol L1. Najaktivniji spojevi 9, 10 i 11 evaluirani su kao radziosenzitirajuća sredstva nakon izlaganja spojeva γ-zračenju (8 kGy)

Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over- or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron emission tomography (PET) images. Since this degrades the diagnostic quality of the images, metal artefact reduction (MAR) prior to attenuation correction is required

Acyloxylation of Cyclic Enones: Synthesis of Densely Oxygenated Guaianolides

The α′-acyloxylation of cyclic enones with linear carboxylic acids is described. The reaction is promoted by KMnO4 in the presence of a carboxylic acid and its corresponding carboxylic anhydride. The optimization of the reaction has been carried out using the statistical methodology known as design of experiments. The optimized reaction conditions have been evaluated in terms of substrate scope and compatibility with different functional groups. The methodology has been applied to the synthesis of densely oxygenated guaianes and guaianolides

Radionuclide Imaging of Viable Myocardium: Is it Underutilized?

Coronary artery disease is the major cause of heart failure in North America. Viability assessment is important as it aims to identify patients who stand to benefit from coronary revascularization. Radionuclide modalities currently used in the assessment of viability include 201Tl SPECT, 99mTc-based SPECT imaging, and 18F-fluorodexoyglucose (18F-FDG)-PET imaging. Different advances have been made in the last year to improve the sensitivity and specificity of these modalities. In addition, the optimum amount of viable (yet dysfunctional) myocardium is important to identify in patients, as a risk–benefit ratio must be considered. Patients with predominantly viable/hibernating myocardium can benefit from revascularization from a mortality and morbidity standpoint. However, in patients with minimal viability (predominantly scarred myocardium), revascularization risk may certainly be too high to justify revascularization without expected benefit. Understanding different radionuclide modalities and new developments in the assessment of viability in ischemic heart failure patients is the focus of this discussion

Genetic analysis of typical wet-type age-related macular degeneration and polypoidal choroidal vasculopathy in Japanese population

Age-related macular degeneration (AMD) is a common cause of blindness in the elderly. Caucasian patients are predominantly affected by the dry form of AMD, whereas Japanese patients have predominantly the wet form of AMD and/or polypoidal choroidal vasculopathy (PCV). Although genetic association in the 10q26 (ARMS2/HTRA1) region has been established in many ethnic groups for dry-type AMD, typical wet-type AMD, and PCV, the contribution of the 1q32 (CFH) region seem to differ among these groups. Here we show a single nucleotide polymorphism (SNP) in the ARMS2/HTRA1 locus is associated in the whole genome for Japanese typical wet-type AMD (rs10490924: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p = 4.1 \times 10 ^{ - 4}$$\end{document}, OR = 4.16) and PCV (rs10490924: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p = 3.7 \times 10 ^{ -8}$$\end{document}, OR = 2.72) followed by CFH (rs800292: \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p = 7.4 \times 10 ^{ -5}$$\end{document}, OR = 2.08; \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p = 2.6 \times {10^{ - 4}}$$\end{document}, OR = 2.00), which differs from previous studies in Caucasian populations. Moreover, a SNP (rs2241394) in complement component C3 gene showed significant association with PCV (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p = 2.5 \times {10^{ - 3}}$$\end{document}, OR = 3.47). We conclude that dry-type AMD, typical wet-type AMD, and PCV have both common and distinct genetic risks that become apparent when comparing Japanese versus Caucasian populations